Comparative Effectiveness of Intravascular Stents in Resisting Arterial Vasoconstriction: Evaluation with Use of Intact Elastic (Rabbit Aorta) and Muscular (Dog Carotid) Arteries in an ex Vivo Model

Purpose: The ability of three different intravascular stents (Gianturco-Roubin, Palmaz-Schatz, and CV Rad), and two different metals (stainless steel and tantalum) to resist vasoconstriction was evaluated in an intact artery ex vivo model. Materials and Methods: Stents were deployed in 21 rabbit thoracic aortae and five dog carotid arteries, which were constricted with phenylephrine and serotonin, respectively. Vasoconstriction was measured with the use of high-frequency ultrasonic imaging. Results: The maximal vasoconstriction of the control segment was 37.7% ± 2.6 with rabbit aortae and 36.3% ± 4.1 with dog carotid arteries, while the average maximal constriction for all segments in which stents were placed was 5.7% ± 1.1 (P < .01). The maximal constriction of the Gianturco-Roubin stainless steel stent was 9.4% ± 2.7 versus 7.9% ± 1.6 with the tantalum version (P = .65). Both designs showed somewhat greater constriction compared with either the Palmaz-Schatz (3.3% ± 0.9) or the CV Rad (1.4% ± 1.1) stents. Conclusions: Although all of the stents tested substantially resist arterial vasoconstrictive forces, the Palmaz-Schatz and CV Rad stents resist vasoconstriction to a greater degree than the Gianturco-Roubin stents. Tantalum and stainless steel stents of the same design (Gianturco-Roubin) appear similar in their ability to resist vasoconstrictive forces.